[BUG] DynamoDB source has potential for invalid mappings to OpenSearch

[graytaylor0]

Describe the bug
DynamoDb and OpenSearch mappings have potential for conflicts. One example of this being hit is with the Number type in DDB supporting both float and long types.

With dynamic mappings in OpenSearch, the first document that gets created will determine the mappings. Following documents with different types for the same field would result in mapping failures.

For example, the DynamoDb Number type can represent float, long, etc, while OpenSearch has explicit typing for float and long

Testing earlier with a field with a mix of float and long types for a field resulted in this exception sending to a serverless collection

2023-10-27T15:58:48,210 [dynamodb-pipeline-sink-worker-2-thread-1] WARN  org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink - Document failed to write to OpenSearch with error code 400. Configure a DLQ to save failed documents. Error: mapper [cs_ship_customer_sk] cannot be changed from type [long] to [float]
2023-10-27T15:58:48,210 [dynamodb-pipeline-sink-worker-2-thread-1] WARN  org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink - Document failed to write to OpenSearch with error code 400. Configure a DLQ to save failed documents. Error: mapper [cs_ship_customer_sk] cannot be changed from type [long] to [float]
2023-10-27T15:58:48,210 [dynamodb-pipeline-sink-worker-2-thread-1] WARN  org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink - Document failed to write to OpenSearch with error code 400. Configure a DLQ to save failed documents. Error: mapper [cs_net_paid_inc_ship] cannot be changed from type [float] to [long]
2023-10-27T15:58:48,210 [dynamodb-pipeline-sink-worker-2-thread-1] WARN  org.opensearch.dataprepper.plugins.sink.opensearch.OpenSearchSink - Document failed to write to OpenSearch with error code 400. Configure a DLQ to save failed documents. Error: mapper [cs_quantity] cannot be changed from type [long] to [float]

We need to define an index mapping template that can handle all types of DynamoDB types (https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.NamingRulesDataTypes.html) to OpenSearch types (https://opensearch.org/docs/2.4/opensearch/supported-field-types/numeric/)

Expected behavior
Provide a guide for creating index mappings for ddb to opensearch. We can supply this as template_content.

Additional context
Add any other context about the problem here.

[christopheranderson]

Could we include primary key info in the error context?